Chapter 8: Sensory, Processing, Touch, and Pain Flashcards
Sensory Receptor Organ
An organ specialized to receive particular stimuli
Stimulus
A physical event that triggers a sensory response
Receptor Cell
A specialized cell that responds to a particular energy or substance in the internal or external environment and converts energy into a change in the electrical potential across the membrane.
Adequate Stimulus
The type of stimulus for which a given sensory organ is particularly adapted
Specific Nerve Energies
The doctrine that the receptors and neural channels for the different senses are independent and operate in their own special ways and can produce only one particular sensation each.
Labeled Lines
The concept that each nerve input to the brain reports only a particular type of information
Sensory Transduction
The process in which a receptor cell converts the energy in a stimulus into a change in the electrical potential across its membrane
Receptor Potential
A skin receptor cell type that detects vibration
Threshold
The stimulus intensity that is just adequate to trigger an action potential
Coding
The rules by which action potentials in a sensory system reflect a physical stimulus
Range Fractionation
A hypothesis of stimulus intensity perception stating that a wide range of intensity values can be encoded by a group of cells, each of which is a specialist for a particular range of stimulus intensities
Somatosensory
Referring to body sensation, particularly touch and pain sensation.
Adaptation
Here, the progressive loss of receptor sensitivity as stimulation is maintained
Tonic Receptor
A receptor in which the frequency of action potentials declines slowly or not at all as stimulation is maintained
Phasic Receptor
A receptor in which the frequency of action potentials drops rapidly as stimulation is maintained
Top-Down Process
A process in which higher-order cognitive processes control lower-order systems, often reflecting conscious control
Sensory Pathways
The chain of neural connections from sensory receptor cells to the cortex
Thalamus
The brain regions at the top of the brainstem that trade information with the cortex
Receptive Feild
The stimulus region and features that affect the activity of a cell in a sensory systems
Primary Sensory Cortex
For the given sensory modality, the region of the cortex that receives most of the information about the modality from he thalamus or, in the case of olfaction, directly form the secondary sensory neurons
Secondary Sensory Cortex
Also called “non-primary sensory cortex”. For a given sensory modality, the cortical regions receiving direct projections from primary sensory cortex for that modality
Primary Somatosensory Cortex
Also called “somatosensory 1”. The gyrus just posterior to the central sulcus, in the partial lobe, where sensory receptors on the body surface are mapped; primary cortex for receiving touch and pain information
Secondary Somatosensory Cortex
Also called “somatosensory 2”. The region of the cortex that receives direct projections from primary somatosensory cortex
Attention
A state or condition of selective awareness or perceptual receptivity, by which specific stimuli are selected for enhances processing
Cingulate Cortex
Also called “Cingulum”. A region of the medial cerebral cortex that lies dorsal to the corpus callosum
Polymodal
Involving several sensory modalities
Synesthesia
A condition in which stimuli in one modality evoke the involuntary experience of an additional sensation in another modality
Epidermis
the outermost layer of skin, over the dermis
Dermis
the middle layer of skin, between the epidermis and the hypodermis
Hypodermis
Also called “Subcutaneous tissue”
Tactile
Of or relating to touch
Meissners Corpuscle
A skin receptor cell type that detects light touch
Merkel’s Disc
A skin receptor cell type that detects fine touch
Piezo
A family of two proteins that responds to mechanical stretch by opening channels to let cations in to depolarize
Ruffini’s Ending
A skin receptor cell type that detects stretching of the skin
Dorsal Column System
A somatosensory system that delivers most touch stimuli via the dorsal columns of spinal white matter to the brain
Dorsal Column Nuclei
Collection of neurons in the medulla that receive somatosensory information via the dorsal columns of spinal cord. These neurons send their axons across the midline and to the thalamus
Dermatome
A strip of skin innervated by a particular spinal nerve
Pain
The discomfort normally associated with tissue damage
Congenital Insensitivity to Pain
The condition of being born without the ability to perceive pain
Noniceptor
A receptor that responds to stimuli that produce tissue damage or pose the threat of damage
Free Nerve Ending
An axon that terminates in the skin without any specialized cell associated with it and that detects pain and?or changes in temperature
Capsaicin
A compound synthesized by various plants to deter predators by mimicking the experience of burning
Transient Receptor Potential Vanilloid Type 1 (TRPV1)
Also called “Vanilliod Receptor 1”. A receptor that bins capsaicin to transmit the burning sensation from chili peppers and normally detects sudden increases in temperature
Transient receptor Potential Type M3(TRPM3)
A receptor, found in some free nerve endings, that opens its channel in response to rising temperatures
A delta fiber
A moderately large, myelinated, and therefore fast- conducting axon, usually transmitting acute pain information
C fiber
A small, unmyelinated axon that conducts pain information slowly and adapts slowly
TRPM8
Also called “cool-menthol receptors 1 (CMR1)”. A sensory receptor, found in some free nerve endings, that opens an ion channel in response to a mild temperature drop or exposure to menthol
Na(v)1.7
Also called “SCN9A”. A voltage-gated sodium channel used almost exclusively by nociceptors to initiate action potentials
Anterolateral System
Also called “Spinothalamic Systems”. A somatosensory system that carries most of the pain and temperature information from the body to a brain
Glutamate
An amino acid transmitter; the most common excitatory transmitter
Substance P
A peptide transmitter implicated in pain transmission
Natriuretic Polypeptide B (Nppb)
A peptide neurotransmitter used by neurons reporting itch to the spinal cord
Neuropathic Pain
Pain caused by damage to peripheral nerves. It is often difficult to treat
Migraines
Intense headaches, typically perceives from one half of the head, that recur regularly and can be difficult to treat
Cannabis
Dried leaves and flowers of the plant Cannabis sativa, typically smoked to obtain THC for a psychoactive effect
Analgesia
Absence of or reduction of pain
Opiates
A class of compounds that exert an effect like that of opium, including reduced pain sensitivity
Endogenous Opioids
A class of peptides produces in various regions of the brain that bind to opioid receptors and act like opioids
Endorphins
One of three kinda of endogenous opioids, substances that reduce pain perception
Enkephalins
One of three kinds of endogenous opioids, substances that reduce pain perception
Dynorphines
One of three kinds of endogenous opioids, substances that reduce pain perception
Opioid Receptors
A receptor that responds to endogenous and/ or exogenous opioids
Periaqueductal Gray
The neuronal body-rich region of the midbrain surrounding the cerebral aqueduct that connects the third and fourth ventricles. It is involved in pain perception.
Placebo
A substance that is known to be ineffective or inert but that, when administered like a drug, can sometimes bring relief.
Naloxone
A potent antagonist of opiates that is often administered to people who have taken drug overdoses. It blocks receptors for endogenous opioids
Nocebo
An inert substance that causes discomfort due to the patients expectations
